1) Field of the Invention
The invention concerns an autonomous timepiece with an electromagnetic transducer built into a case for an electromechanical display, the transducer being magnetically decoupled from an antenna connected to a receiver.
2) Description of Related Art
A timepiece of this type is described for example in DE-OS 35 10 637 which introduced to the market the JUNGHANS radio timepiece technology. It is not necessary to locate a magnetic long-wave antenna outside the timepiece (for example, in an inhabited room) and it may be installed in the casing of the timepiece. However, the antenna must be placed as far as possible from the case. If, for reasons of the circuitry required the radio timepiece mechanism, the timepiece is equipped a tuned radio-frequency receiver, rather than a superheterodyne receiver, there might be interfering reactions, particularly from the electromagnetic transducer. While with a superheterodyne receiver, the intermediate frequency conversion may result in decoupling.
When equipping a radio timepiece with a tuned radio-frequency receiver, the relatively large mass of the antenna coil, together with the ferrite core extending through it, must be connected externally with the receiver circuit by means of a long flexible cable. The long flexible cable is cumbersome and prone to failure, for example, in shipping or in the installation of such a radio timepiece mechanism in the mountings of a saleable consumer timepiece.